LTR-TEs abundance, timing and mobility in Solanum commersonii and S. tuberosum genomes following cold stress conditions

From an evolutionary perspective, retrotransposons (LTR-RTs) activity during stressmay be viewed as a mean by which organisms can keep up rates of geneticadaptations to changing conditions. Potato is one of the most important cropconsumed worldwide, but studies on LTR-RT characterization are still lacking. Here,we assessed the abundance, insertion time and activity of LTR-RTs in both cultivatedSolanum tuberosum and its cold tolerant wild relative S. commersonii genomes. Gypsyelements abounded more than Copia ones, suggesting that the former were somehowmore successful in colonizing potato genomes. However, Copia elements, and inparticular the Ale lineage, are younger than Gypsy ones, since their insertion time wasin average ~ 2 Mya. Due to the ability of LTR-RTs to be circularized by the host DNArepair mechanisms, we identified a Copia/Ale element active (called nightshade,informal name used for potato family) in S. tuberosum genome via mobilome-seq, inline with their young insertion time. Our analyses represent a valuable resource forcomparative genomics within the Solanaceae, transposon-tagging and for the designof cultivar-specific molecular markers in potato.